Will ducklings use their house on their own?

I have 7 ducklings. I JUST put them outside two days ago. Unfortunately, the weather has not been in my favor, and it's been raining like crazy. Every time it rains, the ducklings...just walk around in the rain and they just "yap" or cry, I'm not really sure. I go out there and put them inside of their house. They seem happy once they're in the house, but they don't seem to want to use it unless I literally put them inside of it. It also takes a bit for them to come outside, but that's another story.

They're NOT fully feathered, but the temperatures have been good except for the awful rain. Basically, my question is the title. Will they actually use their house on their own if they get too cold/wet?? It sucks having to put them in their house and lock them in at 3pm because it starts raining. AND THEN it stops literally less than 5 minutes after I put them in

Once they are fully feathered they will be fine but until then it is best to keep them from getting too chilled. Ducklings that have had swim time before going out will know how to groom themselves to dry off but if they have not done much self grooming already they may not know how to dry off on their own. The down does not provide much insulation so they will need a heat source to warm up.

Chances are the house is dry but not warm (birds instinctively use the sun to warm themselves) so they will not go inside on their own due to a duck's natural instinct to avoid places where they can become trapped. You will need some sort of a comfort incentive for them to go inside on their own, such as heat or food.